You've made some very good points. We have talked about the sound in the past, and though some viewers hate not being able to hear each line completely distinctly, I, myself, prefer the realism of the background distractions. This is what it would really sound like, were you "there" trying to talk to someone. In many films, these background noises are "tamped" down and the dialog pumped up a bit for clarity. I prefer it this way, even if I have to watch a couple more times (100+?)to understand each line!